There currently exists in the market interchangeable cores (ICs) for lock core assemblies that allow a door to be quickly re-keyed without removing a cylindrical lock core assembly from a door. A special “change” key allows the IC to be readily removed from the cylindrical housing of the assembly without removal of the lock core assembly from the door. A standard key inserted in the IC allows rotation of the cylinder to disengage a latch from an associated strike. The prior art IC component of the lock core assembly includes a cylindrical IC housing, an IC insert and the IC itself. A “cam” is attached to the IC component for rotation with the IC. The cam acts on a locking train provided in the latch assembly to unlock the latch. Threads are formed on the outer surface of the cylindrical housing and the IC component is screwed into the latch assembly to secure it in place.
Although, this design has served the industry well, there exist many drawbacks to this design. For example, the lock core assembly of the prior art design extends beyond the outer surface of a narrow stile door thereby exposing the assembly to outside lateral forces. It would be beneficial from both a security and aesthetics perspective if the device could be flush on both sides of the door, or at least on the “secure side” of the door. (The term “secure side” as used herein means the side of the door that could be exposed to unwanted intruders). Also, since the prior art housing is threaded on its outside surface for assembling into the latch assembly, the housing requires extensive machining, is expensive to manufacture and the threads can be damaged during installation. Further, since the prior art housing is cylindrical in shape, the lock core assembly is vulnerable to a forced twisting by an intruder to break it free from the latch assembly.
Still further, because of the design of the prior art locking train wherein a lever component partially blocks the opening that receives the lock core assembly, the housing of the lock core assembly must be formed into two sections in order for it to be installed into the latch assembly, thereby increasing part costs and costs of installation.
Finally, often times it is necessary to replace a thumb-turn component on the non-secure side with a key lockable component so that a key lock is provided on both sides of the lock core assembly. In the prior art, this task often resulted in having to exchange the entire lock core assembly which is time consuming, labor intense and costly.
It is a principal object of the present invention to provide a flush-mounted lock core assembly that is less vulnerable than prior art assemblies to tampering by hammer blows made either radially or axially.
It is a still further object of the present invention to increase the versatility of a lock core assembly in a plurality of lock configurations.
It is a still further object of the present invention to provide a lock core assembly having a non-cylindrical housing that inherently resists forced twisting.
It is a still further object of the present invention to install a lock core assembly into a latch assembly without the use of threads.